Questions and Answers
What are Wolf-Rayet stars primarily characterized by?
Who discovered Wolf-Rayet stars?
C.J.E. Wolf and G. Rayet
More than 220 Wolf-Rayet stars have been identified.
True
What are the wind speeds of Wolf-Rayet stars?
Signup and view all the answers
What is AB7 also known as?
Signup and view all the answers
Which star is classified as a luminous blue variable?
Signup and view all the answers
AG Pegasi is a binary system composed of a red giant and a white dwarf.
Signup and view all the answers
What is the approximate location of CD Crucis?
Signup and view all the answers
What is the composition of HD 38282?
Signup and view all the answers
R136a1 is known for being one of the most massive stars at what mass?
Signup and view all the answers
What makes hypernovae distinct?
Signup and view all the answers
Study Notes
Wolf-Rayet Stars
- Discovered by C.J.E. Wolf and G. Rayet at Paris Observatory in 1867, with over 220 identified.
- Characterized by extremely high temperatures ranging from 25,000 to 100,000 K.
- Experience mass loss exceeding 10^-5 Solar masses per year.
- Wind speeds can reach between 800 to over 3,000 kilometers per second.
- Typically exhibit rapid rotation and can start from masses under 20 Solar masses; lack dramatic variability.
AB7
- Known as SMC WR7, this binary star is found in the Small Magellanic Cloud.
- Comprises a Wolf-Rayet star and a supergiant companion of spectral type O with a 19.56-day orbital period.
- Surrounded by a bubble nebula.
AB8
- Also referred to as SMC WR8, a binary star in the Small Magellanic Cloud.
- Consists of a Wolf-Rayet star and a main sequence companion of spectral type O, orbiting every 16.638 days.
- Notable for being one of only nine known WO stars and the only one in the SMC not on the nitrogen sequence.
AG Carinae
- A luminous blue variable star in the constellation Carina.
- Recognized as one of the most luminous stars in the Milky Way.
AG Pegasi
- A symbiotic binary star located in the constellation Pegasus, composed of a red giant and a white dwarf.
- The primary has a mass of approximately 2.5 Solar masses, while the secondary is around 0.6 Solar masses.
- Classified as a symbiotic nova with a history of outbursts.
Apep
- A triple star system located in the constellation Norma, including a Wolf-Rayet binary and a hot supergiant.
- Named after the Egyptian serpent deity and surrounded by stellar wind and cosmic dust forming a "pinwheel" shape.
- Identified as a prominent gamma-ray burst progenitor candidate in the Milky Way.
Arches Cluster
- The densest known star cluster in the Milky Way, situated about 100 light-years from its center in Sagittarius.
- Discovered in 1995 and obscured by heavy optical extinction; observed in X-ray, infrared, and radio bands.
- Home to approximately 135 young, massive stars, alongside thousands of less massive stars.
BAT99-98
- A massive star located in the Large Magellanic Cloud, near the R136 cluster in the 30 Doradus nebula.
- Rated at 226 Solar masses and 5,000,000 Solar luminosities, making it one of the most massive and luminous stars.
CD Crucis
- Known as HD 311884, an eclipsing binary star in the constellation Crux, approximately 14,000 light-years away.
- Contains a Wolf-Rayet star, also designated WR 47.
Cygnus X-3
- A high-mass X-ray binary (HMXB) considered a microquasar.
- The only known HMXB with a Wolf-Rayet star, pulling gas from an ordinary star companion.
- Invisible to the naked eye; observable in radio, infrared, X-ray, and gamma-ray spectra.
EZ Canis Majoris
- A binary system in Canis Major, highlighted as one of the ten brightest Wolf-Rayet stars.
- Its primary Wolf-Rayet star shines at an apparent magnitude brighter than 7.
Gamma Velorum
- A quadruple star system in the constellation Vela, one of the brightest stars with a combined magnitude of +1.7.
- Contains the closest and brightest Wolf-Rayet star, known traditionally as Suhail al Muhlif, and modernly as Regor.
GCIRS 13E
- An infrared and radio object near the galactic center, suspected to be a cluster of hot massive stars.
- Potentially harbors an intermediate-mass black hole at its core.
GCIRS 16SW
- A contact binary star in the Galactic Center, with both stars of equal size in orbit every 19.5 days.
- Atmospheres overlap, creating an eclipsing binary with a brightness variation of 0.35 magnitudes in infrared.
HD 5980
- A multiple star system located in NGC 346 within the Small Magellanic Cloud and recognized as one of its brightest stars.
HD 38282
- A massive spectroscopic binary star located within the Tarantula Nebula, made up of two hydrogen-rich Wolf-Rayet stars.
HD 97950
- A multiple star system classified initially as a single star but revealed to be a massive star cluster in the NGC 3603 region.
HD 151932
- A Wolf-Rayet star in the constellation Scorpius, located about 1,300 parsecs from Earth.
- Extremely reddened by interstellar extinction; one of the few visible Wolf-Rayet stars to the naked eye.
Hypernova
- Generated when a very massive star collapses into a black hole.
- Considered a potential source of gamma-ray bursts.
LH41-1042
- A Wolf-Rayet star in the Large Magellanic Cloud and a rare member of the WO oxygen sequence.
LMC195-1
- Another Wolf-Rayet star in the Large Magellanic Cloud, classified as a WO2, likely among the hottest stars known.
Melnick 34
- A binary Wolf-Rayet star located near R136 in the 30 Doradus complex, consisting of highly luminous components.
Romano's Star
- A luminous blue variable star in the Messier 33 galaxy, situated in the constellation Triangulum.
Theta Muscae
- A multiple star system in Musca, recognized as the second-brightest Wolf-Rayet star despite contributions from other massive companions.
VFTS 682
- A Wolf-Rayet star situated in the Large Magellanic Cloud, over 29 parsecs from R136.
- Notable for having 150 Solar masses and 3.2 million Solar luminosities.
Westerlund 2
- An obscured young star cluster about 20,000 light-years away in Carina, estimated to be 1-2 million years old.
- Features some of the hottest and most massive stars known.
NGC 2867
- An elliptical Type II planetary nebula located in the southern constellation Carina.
NGC 3603-A1
- A double-eclipsing binary star at the center of the HD 97950 cluster, notable for being among the most luminous stars.
NGC 3603-B
- A Wolf-Rayet star residing at the center of the HD 97950 cluster, classified as WN6h and highly luminous.
NGC 3603-C
- A single-lined spectroscopic binary system in the HD 97950 cluster, noted for its massive, luminous primary.
R71
- A luminous blue variable star located in the Large Magellanic Cloud with significant luminosity.
R99
- Another highly luminous star in the Large Magellanic Cloud, classified as a possible luminous blue variable.
R136a1
- One of the most massive and luminous stars at 215 Solar masses and 6.2 million Solar luminosities, found at the center of R136 in the Tarantula Nebula.
R136a2
- A prominent Wolf-Rayet star near the center of R136 with a confirmed mass of about 187 Solar masses and luminosity of 5.6 million.
R136a3
- Located near R136a1, this Wolf-Rayet star is one of the most massive and luminous, at 154 Solar masses.
R136b
- A highly luminous Wolf-Rayet star within the R136 cluster in the Large Magellanic Cloud.
R136c
- A massive star in R136, noted for its luminosity and temperature over 40,000 K.
R145
- A spectroscopic binary star in the Tarantula Nebula, both components noted for their exceptional luminosity.
Superluminous Supernovae
- 10 to 100 times brighter than typical supernovae, characterized by long rise times indicating significant mass.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the fascinating world of Wolf-Rayet stars and their characteristics. This quiz covers key definitions and facts about these massive, rapidly rotating stars, including their identification and mass loss rates.
